{
* FmPreviewDlg.pas
*
* Implements a dialog box that is used to preview or display text, HTML and
* Rich text documents.
*
* $Rev$
* $Date$
*
* ***** BEGIN LICENSE BLOCK *****
*
* Version: MPL 1.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License for
* the specific language governing rights and limitations under the License.
*
* The Original Code is FmPreviewDlg.pas
*
* The Initial Developer of the Original Code is Peter Johnson
* (http://www.delphidabbler.com/).
*
* Portions created by the Initial Developer are Copyright (C) 2005-2009 Peter
* Johnson. All Rights Reserved.
*
* Contributor(s)
* NONE
*
* ***** END LICENSE BLOCK *****
}
unit FmPreviewDlg;
interface
uses
// Delphi
ImgList, Controls, Classes, ActnList, Menus, Forms, ComCtrls, StdCtrls,
ExtCtrls,
// Project
FmGenericViewDlg, FrBrowserBase, FrHTMLPreview, FrMemoPreview, FrRTFPreview,
FrTextPreview, IntfPreview, UBaseObjects;
type
{
TPreviewDlg:
Dialog box used to preview text, HTML and Rich text documents.
}
TPreviewDlg = class(TGenericViewDlg, INoPublicConstruct)
actCopy: TAction;
actSelectAll: TAction;
alPreview: TActionList;
frRTF: TRTFPreviewFrame;
frHTML: THTMLPreviewFrame;
frText: TTextPreviewFrame;
ilPreview: TImageList;
miCopy: TMenuItem;
miSelectAll: TMenuItem;
mnuPreview: TPopupMenu;
pcViews: TPageControl;
tsHTML: TTabSheet;
tsRTF: TTabSheet;
tsText: TTabSheet;
procedure actCopyExecute(Sender: TObject);
procedure actCopyUpdate(Sender: TObject);
procedure actSelectAllExecute(Sender: TObject);
procedure actSelectAllUpdate(Sender: TObject);
procedure FormClose(Sender: TObject; var Action: TCloseAction);
strict private
fViewer: IInterface; // Interfaces with viewer frame
fDocContent: string; // Stores content of document we are displaying
fDlgTitle: string; // Dialog box title
procedure GetViewerInfo(out Viewer: IInterface; out TabSheet: TTabSheet);
{Gets information about required document viewer and tab sheet that
contains it.
@param Viewer [out] Interface to viewer frame.
@param TabSheet [out] Tab sheet containing viewer frame.
}
function CanCopy: Boolean;
{Checks if current view supports copying to clipboard.
@return True if copying supported.
}
function CanSelectAll: Boolean;
{Checks if current view supports text selection.
@return True if selection supported.
}
procedure CopyToClipboard;
{Copies selected text to clipboard from current view if view supports
copying.
}
procedure SelectAll;
{Selects all text in current view if view supports selection.
}
strict protected
procedure InitForm; override;
{Loads and displays the document being previewed.
}
public
class procedure Execute(AOwner: TComponent; const ADocContent: string;
const ADlgTitle: string = '');
{Displays a document in the preview dialog.
@param AOwner [in] Owning component.
@param ADocContent [in] Content of document to be displayed (HTML, RTF
or plain text).
@param ADlgTitle [in] Title of dialog box. Default is used if ''.
}
end;
implementation
uses
// Delphi
SysUtils,
// Project
IntfFrameMgrs, URTFUtils, UHTMLUtils;
{$R *.dfm}
{ TPreviewDlg }
procedure TPreviewDlg.actCopyExecute(Sender: TObject);
{Copies preview text to clipboard.
@param Sender [in] Not used.
}
begin
CopyToClipboard;
end;
procedure TPreviewDlg.actCopyUpdate(Sender: TObject);
{Enables / disables Copy action depending or whether copying is supported in
current view.
@param Sender [in] Not used.
}
begin
actCopy.Enabled := CanCopy;
end;
procedure TPreviewDlg.actSelectAllExecute(Sender: TObject);
{Selects all preview text.
@param Sender [in] Not used.
}
begin
SelectAll;
end;
procedure TPreviewDlg.actSelectAllUpdate(Sender: TObject);
{Enables / disables Select All action depending on whether selection is
supported in current view.
@param Sender [in] Not used.
}
begin
actSelectAll.Enabled := CanSelectAll;
end;
function TPreviewDlg.CanCopy: Boolean;
{Checks if current view supports copying to clipboard.
@return True if copying supported.
}
begin
Result := False;
if Supports(fViewer, IClipboardMgr) then
Result := (fViewer as IClipboardMgr).CanCopy;
end;
function TPreviewDlg.CanSelectAll: Boolean;
{Checks if current view supports text selection.
@return True if selection supported.
}
begin
Result := False;
if Supports(fViewer, ISelectionMgr) then
Result := (fViewer as ISelectionMgr).CanSelectAll;
end;
procedure TPreviewDlg.CopyToClipboard;
{Copies selected text to clipboard from current view if view supports copying.
}
begin
if Supports(fViewer, IClipboardMgr) then
(fViewer as IClipboardMgr).CopyToClipboard;
end;
class procedure TPreviewDlg.Execute(AOwner: TComponent;
const ADocContent: string; const ADlgTitle: string = '');
{Displays a document in the preview dialog.
@param AOwner [in] Owning component.
@param ADocContent [in] Content of document to be displayed (HTML, RTF or
plain text).
@param ADlgTitle [in] Title of dialog box. Default is used if ''.
}
begin
with InternalCreate(AOwner) do
try
fDlgTitle := ADlgTitle;
fDocContent := ADocContent;
ShowModal;
finally
Free;
end;
end;
procedure TPreviewDlg.FormClose(Sender: TObject; var Action: TCloseAction);
{Frees viewer object whether form is closed.
@param Sender [in] Not used.
@param Action [in] Not used.
}
begin
inherited;
fViewer := nil; // required to prevent access violation
end;
procedure TPreviewDlg.GetViewerInfo(out Viewer: IInterface;
out TabSheet: TTabSheet);
{Gets information about required document viewer and tab sheet that contains
it.
@param Viewer [out] Interface to viewer frame.
@param TabSheet [out] Tab sheet containing viewer frame.
}
begin
if URTFUtils.IsValidRTFCode(fDocContent) then
begin
// RTF document
TabSheet := tsRTF;
Viewer := frRTF;
end
else if UHTMLUtils.IsValidHTMLCode(fDocContent) then
begin
// HTML document
TabSheet := tsHTML;
Viewer := frHTML;
end
else
begin
// Plain text document
TabSheet := tsText;
Viewer := frText;
end;
end;
procedure TPreviewDlg.InitForm;
{Loads and displays the document being previewed.
}
var
TabSheet: TTabSheet; // tab sheet containing preview frame
Title: string; // document title
begin
inherited;
// Display document (select tab, load doc and set submenu on into frame)
GetViewerInfo(fViewer, TabSheet);
// select tab containing required frame
pcViews.ActivePage := TabSheet;
// update required frame's popup menu and display document in it
(fViewer as IPreview).SetPopupMenu(mnuPreview);
// load content into preview and set dialog caption
(fViewer as IPreview).Display(fDocContent, Title);
if fDlgTitle <> '' then
Caption := fDlgTitle // caller specified title - use it
else if Title <> '' then
Caption := Caption + ': ' + Title; // use title extracted from document
end;
procedure TPreviewDlg.SelectAll;
{Selects all text in current view if view supports selection.
}
begin
if Supports(fViewer, ISelectionMgr) then
(fViewer as ISelectionMgr).SelectAll;
end;
end.
